radial engine master cylinders

the deadly booner · Post by **the deadly booner** » Thu Jan 25, 2007 10:18 am

can someone give me a good answer as to why the failure of the master cylinder on a radial engine is potentially more catastrophic than the failure of any other cylinder?

i saw one gone on a 1340 this summer and it didn't wreck the engine, just the jug. what has to happen to destroy the engine?

Meathead · Post by **Meathead** » Thu Jan 25, 2007 11:27 am

The master Cylinder as the name describes bassically runs all the other cylinders. If you can imagineThe piston of the master being soley attached to big ring in the middle of the engine that all the other pistons run off of. This has potential to cause the whole engine to seize up up if the damage is extensive enough. I know my description was fairly vauge but If you were able to see a diagram of it you may understand a little better.

the deadly booner · Post by **the deadly booner** » Thu Jan 25, 2007 1:00 pm

i know what it looks like inside but it looks like that if any one of the other cylinders seized it would stop the whole show too.

the explanations i have heard in the past weren't entirely clear but they had something to do with the possibility of rings dropping out if the destruction is bad enough or something like that.

twistedoldwrench · Post by **twistedoldwrench** » Thu Jan 25, 2007 8:35 pm

The master rod is held in its relative position to the cylinder by the piston pin. If the rod were to fail, or the piston broke apart, the connecting rod could become "uncentered" if you will relative to the cylinder position, and as a result the other rods could overtravel, allowing the bottom oil control ring to drop out of the bottom of the barrel on their repective cylinders. Once that happens they wont go back up towards TDC very well!

the deadly booner · Post by **the deadly booner** » Fri Jan 26, 2007 1:11 pm

thanks for the reply. that is what i was looking for.